An updated and evidence-based checklist of Mediterranean Sea fishes is provided. Each of the fish species in the Mediterranean Sea listed here was either listed in the last published checklist of the Mediterranean fishes or in other articles, reports or new records, and the checklist is critically assessed. Out of the assessed 791 species previously reported from the Mediterranean, the presence of 759 species is confirmed while 32 species are excluded from the new checklist, by lacking evidence of presence or representing obvious taxonomic confusions. The net increase in known Mediterranean fish species richness since the last checklist is 11%. The non-native Mediterranean species now represent 22.1% (168 species) of the known Mediterranean fish diversity. The evidence-based protocol applied here provides a reliable checklist of marine fishes, for which each of the included species has indeed been recorded at least once within the discussed geographic area in the Mediterranean Sea.

Motivation: Here, we make available a second version of the BioTIME database, which compiles records of abundance estimates for species in sample events of ecological assemblages through time. The updated version expands version 1.0 of the database by doubling the number of studies and includes substantial additional curation to the taxonomic accuracy of the records, as well as the metadata. Moreover, we now provide an R package (BioTIMEr) to facilitate use of the database.Main Types of Variables Included: The database is composed of one main data table containing the abundance records and 11 metadata tables. The data are organised in a hierarchy of scales where 11,989,233 records are nested in 1,603,067 sample events, from 553,253 sampling locations, which are nested in 708 studies. A study is defined as a sampling methodology applied to an assemblage for a minimum of 2 years.Spatial Location and Grain: Sampling locations in BioTIME are distributed across the planet, including marine, terrestrial and freshwater realms. Spatial grain size and extent vary across studies depending on sampling methodology. We recommend gridding of sampling locations into areas of consistent size.Time Period and Grain: The earliest time series in BioTIME start in 1874, and the most recent records are from 2023. Temporal grain and duration vary across studies. We recommend doing sample‐level rarefaction to ensure consistent sampling effort through time before calculating any diversity metric.Major Taxa and Level of Measurement: The database includes any eukaryotic taxa, with a combined total of 56,400 taxa.Software Format: csv and. SQL.